Buffered blower valve



Nbv. 24, 1942. E. G. wEEK BUFFERED BLOWER VALVE I Filed 0ct. 25, 1940 sSheets-Sheet 1 INVENTOR.

Nov. 24,1942. 5, WEEKS 2,303,152

BUFFERED BLOWER VALVE 3 Sheets-Sheet 2 Filed Oct. 25. 1940 I E Eh-Fm gimn' I I 1 1 INVENTOR.

Patented Nov. 24, 1942 iJNi'iED stares e'-'.rss rf,orrice Edmund GeorgeWeeks, London, England, assign. or to Diamond Power SpecialtyCorporation, Detroit, Miclr, a corporation'of Michigan ApplicationOctober 25, 1940, Serial No. 362,785 In Great Britain October 25, 1939 2Claims. (01. 137-139) This invention relates to fluid heater cleaners ofthe kind comprising a blower tube and a normally closed control valvefor-controlling the flow of cleaning fluid to the blower tube, the valvebeing operable by a piston arranged during service to move the controlvalve from the open to the closed position when the-pressure onone sideof the piston is raised to a sufiicient degree through the leakage ofcleaning fluid to that side of the piston while an auxiliary valve forcontrolling the escape of fluid from the one side of the piston isclosed, together with means arranged automatically to open the auxiliaryvalve when the blower tube is in a predetermined position in order torelease'the pressure on the one side of the piston and whereby to efiectopening of the control valve and admission of cleaning fluid to theblower tube. In a fluid heater cleaner of this kind a definite and rapidopening of the valve is obtainable. advantageous it introduces thedifficulty that the piston is brought to rest with considerable shockwhich may cause damage to the parts affected. An object of theinvention, therefore, is the provision of simple but eiiective means forovercom- 1 ing this difiiculty. 4

In a fluid heater cleaner of the kind specified in accordance with thepresentinvention means are provided'for effecting cushioning of thepiston by preventing or limiting escape of fluid from the one side ofthe piston during the latter part of the opening movement of the controlvalve.

Thus in one form of cleaner or soot blower in accordance with theinvention movement of the piston to open the control valve effectsprevention or limitation of the escape of fluid from the one side of thepiston.

The cleaner may, for example, be of the kind in which the blower tubesimply rotates and is provided with a number of nozzles forthe escape ofcleaning fluid or it may be of the type in which theblower tube carriesat its end a nozzle which together with the blower tube is retractableto a normalposition.

The invention will now be described by way of example with reference tothe accompanying drawings in which:

Figure 1 shows a longitudinal cross section'of a fluid heater cleaneraccording to the invention, with parts of the driving gear broken away;

Figure 2 is a plan View of Figure l, also with parts of the driving gearbroken away; and

Figures' 3 and-4 are sectional side views of the cover plate and..upper.part of the casing and associated members. to a larger .scale thanliig-Whilst the rapid opening is coincide.

ure 1, respectively showing the upper end of the piston with the plungerhalf-way and fully home within the port in the cover plate.

The cleaner illustrated is constructed substantially in the mannerdescribed in the complete specification of co-pending British patentapplication No. 21,696/39 and includes a casing. or pressure part I inwhich is an aperture 2 through. which the blower element including theblower tube 3 extends and in which the element is able to move to andfro, the element being arranged to slide through joints 4 and 5 andprovided respectively in the pressure part I and a tubular extension 6to the pressure part. The pressure part I is also formed with a valvechamber I the longitudinal axis of which is transverse to that of theblower tube 3. Cleaning fluid such as steam'may be admitted to the valvechamber -I through a side opening 8 and the chamber is closed by asleeve or cylinder 9 and a cover plate I0, the lower end of the cylinderseating upon an annular shoulder I I of the pressure part I and theupper end of the. cylinder engaging the surface of an annular recess I 2in the cover plate. The cylinder 9 extends above the top of the pressurepart I and is formed with an annular projection I3 which by engaging thesurface Id of the pressure part ensures that the longitudinal axes ofthe valve chamber I and cylinder 9 shall The cover plate I9 is locatedrelatively to the cylinder 9 by engagement between the annularprojection I5 on the cylinder and the radially outer side of the annularrecess I2. The

cylinder 9'is clamped between the pressure part is provided withbushings I9- and 20 through which a piston rod 2! slides. As shown thebushings I9 and 20 and the co-operatingparts of the piston rod are ofsubstantial diameter so that adequate bearing surfaces are provided foraccurately locating the longitudinal axis of the piston in coincidencewith that of the cylinder. The piston rod 2| is formed in one with'apiston 22 which moves within the cylinder 9, there being a smallclearance 23 between the piston and cyl- I inder for the leakage ofcleaning fluid. It will be appreciated that upon removal of the coverplate ID the cylinder 9 together with piston 22 and valve lid 24 may beremoved as a unit. A fixed valve seat ,25 is screwed into an opening 26:between thevalve chamber ,1 and the aperture 2 and :the "co-operating;valve lid 24 {is carried by the piston, the valve lid being held to abolt 21 by a sleeve 28 encircling the bolt, screwed into the valve lidand engaging the head 29 of the bolt. The bolt 21 passes through thehollow piston rod 2| and the shoulder 30 on the bolt is clamped againstthe end of the piston rod by a nut 3| locked by nut 32, the nuts beingaccommodated in the recess 33 in the piston and piston rod. The valvelid 24 is biassed to the closed position by gravity and by a compressionspring 34 acting between the valve lid and the lower end of cylinder 9or the associated spider. I g r The upper surface of the piston 22 andthe countersunk at 36, coaxial with the piston rod j 2| and bolt 21. Theupper end of the bolt 2! extends above the upper surface of the piston22 and is bevelled to form a plunger 31 arranged to enter the port 35,the arrangement being such that as the plunger 31 moves further into theport 35 the clearance between the plunger and port is progressivelyreduced, as will be clear from Figures 3 and 4. plunger 31 of greatestdiameter of suitable size, the plunger may, if desired, be adaptedsubstantially to prevent escape of fluid through the port 35.

A relay valve 38 includes a spindle 39 the axisof which is disposed in aplane parallel to the axis of the blower tube and a cam 40 on the blowerelement is arranged to transmit movement to the spindle 39 through atappet 4| transverse to the blower tube and a lever 42 inter mediate thespindle and tappet. In the arrange: ment shown the spindle 39 isparallel to the axis of the blower tube, the relay valve 38 beingarranged as a removable unit secured ina recess 43 in the cover plateII], which recess is in communication with the cylinder '9 through theport 35.

The spindle 39 of the relay valve slides through a sleeve 44, the innerend of which is clamped against a shoulder 45 in the recess 43 by athreaddle 39 is of reduced diameter so that when the movable valve ,face49 formed near the inner end of the spindle is moved from the valve seat50 on the sleeve, fluid is able to pass into the annular space :51, andthrough'the ports 48 into the annular space 52 and thence to a duct 53in the cover plate. The spindle 39 is biassed to the closed position bya spring 54 which acts between seatings on the ferrule 45 and a collar55 secured to the spindle and the lever 42 operates the relay valve bypressing against the outer end I of the spindle. 39. The lever 42 ispivoted to,

By making the part of the and the tappet 4| is arranged to slide in abracket 56 secured to the pressure part 4- by studs and nuts 5'! and thelength of the tappet 41 is adjustable, whilst a pin and slot arrangement58 prevents rotation of the tappet 4| and thus maintains properorientation of a roller 59 at the low er end of the tappet 4| inrelation to the cam 40.

The relay valve 38 is arranged to exhaust pressure fluid acting on theupper side of piston 22 to the inner side of a wall 60 of the fluidheater. Thus a tube 6| is arranged to conduct the fluid from the duct 53in cover plate ID to a duct 52 leading to the interior of a wall box 63clamped by screws 64 to the front side of the pressure part I, the tubebeing readily disconnectable from the cover plate ID by means of thejoint 65.

The blower tube 3 is provided with ports 56 and carries a nozzle 51 andis formed in one with a spindle 68. The ports 66 lie always between thejoints 4 and -5 in the annular space 69 between the blower element andaperture 2 and tubular extension 6 so that when the valve lid 24 islifted cleaning fluid is able to flow from the valve chamber 1 throughopening 26 into annular space '69 and through ports 65 blower tube -3and nozzle 61. The spindle 68 carries the cam 40 for operating thetappet 4! when the nozzle 1 61 has been projected from the retractedposition and forms part of suitable operating means including a drivingshaft I0 for moving the blower tube 3 and nozzle 61 axially andefiecting the requisite rotation of the latter.

When pressure fluid is admitted to the valve chamber 1 with the blowertube 3 in its normal or retracted position and the relay valve 3'8closed, pressure fluid leaks past the piston 22 through clearance 23 andraises the pressure in the space H between the piston 22 and cover plateID so that, notwithstanding the pressure exerted by the cleaning fluidon the underside of the piston, the force of gravity and the biassingspring 34 are effective in pressing the valve lid 24 against its fixedseating 25. If, however, the blower tube 3 is advanced, the associatedcam 40, when the nozzle 61 reaches an operative position, throughoperation of tappet 4I-and lever 42 effects opening of the relay valve38 and thereby vents fluid from space H through port 35, duct 53 andtube Bl. The cleaning fluid below the piston, therefore, moves thelatter rapidly upward and quickly lifts the valve lid 24 therebyadmitting cleaning fluid to the aperture 2 in the pressure part! andthence by way of ports 66 to the blower tube. As the piston 22 movestowards its uppermost position the plunger 31 on the bolt 21 by enteringthe port 35 for the escape of fluid exerts a throttling eflfectwhichincreases as the movement proceeds, so that the escape of fluid isrestricted. The fluid thus retained in the space 1| is compressed andserves as a cushion for the piston. Notwithstanding the rapid opening ofthe valve, therefore, the piston and valve are brought to rest graduallyand without shock.

When the cam 40 allows the relay valve 38 to reclose, cleaning fluidleaking through the clearance 23. by raising the pressure in space 1|,effects movement of the valve lid 24 to the closed position.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the same is to be performed, I declare thatwhat I claim is:

1. A fluid control comprising a spring pressed valve having a valve seatguarding a main fluid entry, said valve having an enlarged end at adistance from said valve seat, a cylinder surrounding said enlarged endand having slight normal clearance therewith whereby fluid inlettedbetween said valve seat and said enlarged end may leak past said end, ahead for said cylinder and a relief valve operable by outside influenceto vent the pressure between said cylinder head and said enlarged endwhereby said valve is opened to permit the passage of fluid into saidmain fluid entry, said cylinder head having a passageway leading to saidrelief valve, saidenlarged end having a conical valve atop thereof forseating in the entry to said passageway, said conical valve passagewayleading to said relief valve and terminating at its inlet end in a valveseat, said enlarged end portion having a conical extension thereonarranged for seating in said valve seat upon opening of said reliefvalve, said conical valve having a smaller diameter than that of saidpassageway whereby a restricted flow through said passageway ispermitted.

EDMUND GEORGE WEEK'S.

